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SBC Says IP Data Standard No Cure All

As the transition from IP version 4 to version 6 looms on the horizon, there's no question that IPv4 has surpassed all other standards to date when it comes to data transmission.

Are IPv6 and its predecessor enough to fuel the next surge in demand for Internet services? Regardless of the revised protocols ability to expand limited address space from a 32-bit standard to 128-bit address system, other switching standards remain essential to deliver quality throughput of broadband content.

Ross K. Ireland, SBC Communications' (SBC) senior vice president-network planning and engineering, cautions protocols like Asynchronous Transfer Mode won't go away any time soon. But do expect fiber to play a role as carriers look for ways to improve application speeds.

"IP has clearly won at the edge of the network," Ireland said. "For data services, it's the protocol of choice, and it's already playing a huge role in carrier networks."

Ireland added that the challenge for carriers in the future would be figuring out how to carry the data in the most efficient possible manner.

"Right now, the voice telephone network carries IP data if you dial into your ISP. But that's not the most efficient carriage because of the relatively slow speeds," Ireland said.

"IP doesn't work very well in a voice environment where you have to deal with circumstances like high-volume calling events like a toll-free number for a ticket box office. So, there may not be one right answer, but many alternatives based on optimizing customer applications," Ireland added.

While the quality of data and voice transmission are the immediate industry concerns, bandwidth-intensive applications like streaming audio and video create even greater demands for carriers and ISPs alike.

Ireland said the bigger bandwidth demands require quality throughput.

"If you're going to aggregate service like voice and video with data, the reality is that IP may need help from layer 2 protocols, such as ATM, to provide reliable, high quality service," Ireland explained.

SBC is shooting for throughput rates of at least 1.5 megabits. Ireland said it's the sweet spot for video streaming and entertainment video delivery.

"One-and-a-half megabits will support video streaming, and it is actually quite good for entertainment video," Ireland said. "We have set up our Project Pronto to deliver 1.5 megabit throughput to over 80 percent of our customer base."

"Project Pronto" is SBC's three-year $6 billion broadband initiative launched late last year. The ambitious scheme is designed to deliver broadband services to 80 percent of its customers over the next three years. SBC is pushing fiber and Digital Subscriber Line equipment deeper into its central offices to deploy advanced packet-switching technology.

Consequently, Ireland suggests that IP dominance lacks scalability, and aggregate standards are required for quality data transport.

"IP is not a panacea," Ireland said. Depending on the application, other technologies will remain important."

One of those technologies is asynchronous transfer mode, which SBC uses to carry IP packets at high speeds. According to Ireland, unless engineers can find a way for the IP protocol to take on some of the characteristics of ATM, this protocol will continue to play an important role.

But Ireland contends that carriers and ISPs need to put first things, first.

"Carriers using IP for constant bit-rate services like video streaming have a really difficult time guaranteeing quality of service," Ireland said. "If we can find an economic way to fix the QoS problem, then all we'll be scaling is application speed. And that's okay, because we're going to find solutions on the speed side."